Returning with if else statements

import java.util.Scanner;

public class PracticeQuestionWK4 {
    private static double computeDifference(double first, double second) {
        if (first <= second) {
            System.out.println("First double must be greater than second double, please try again.");
        } else {
            System.out.println(first - second);
        }
        return first - second;
    }

    public static void main(String[] args) {
        Scanner myScanner = new Scanner(System.in);
        System.out.print("Enter first double: ");
        double firstDouble = myScanner.nextDouble();
        System.out.print("Enter second double: ");
        double secondDouble = myScanner.nextDouble();
        computeDifference(firstDouble, secondDouble);
    }

}

This code feels awkward. Is there a purpose using private static double instead of private static void here? The question I'm answering calls for a return but it seems redundant. What should I do?